(12975) Efremov Main-belt Asteroid
Discovered on 28 September 1973 by N. S. Chernykh at Nauchnyj.
Yurij Nikolaevich Efremov (b. 1937) is a leading research scientist at the Sternberg Astronomical Institute, Moscow University. His works on variable stars and star-formation regions are well known. He discovered the period-age relationship for cepheids and created the concept of large complexes of young stars.Naming citation (20050721/MPCPages.arc), IAU / Minor Planet Center, via NASA/JPL
Where Efremov is today
Seen from above the solar system on 2026-10-14: Efremov is 2.82 au from the Sun and 3.34 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 12975 |
| Provisional designation | 1973 SY5 |
| Orbit class | Main-belt Asteroid |
| Diameter | 6.75 km (#7,942 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.169 |
| Absolute magnitude (H) | 13.36 |
| Orbital period | 4.16 years |
| Semi-major axis | 2.59 au |
| Perihelion – aphelion | 2.22 – 2.95 au |
| Eccentricity | 0.142 |
| Inclination | 15.1° |
| Closest distance between its orbit and Earth's (MOID) | 1.24 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.